1. Field of the Invention
The invention generally relates to arrangements for managing telephone calls carried by Voice over Internet Protocol (VoIP) technology. More particularly, the invention relates to arrangements for enabling users to manage or avoid unsolicited or undesired VoIP calls that constitute spam over Internet telephony (SPIT).
2. Related Art
Telephone calls have become progressively less expensive. As communications costs continue to decrease, the cost of placing a telephone call, particularly one employing voice over Internet protocol (VoIP) technology, approaches zero. The ability to place a call for essentially no incremental cost makes it feasible for marketers to place unsolicited telephone calls—either interactive or with recorded messages—to extremely large quantities of telephone numbers. The evolution toward ubiquity of telephony over the Internet in the form of IP-UNE (Internet Protocol Unbundled Network Element-Line) devices, and particularly in the form of VoIP, makes spam over Internet telephony (SPIT) a problem even to those users who don't realize they are using a VoIP device.
The United States Federal Communications Commission (FCC) determined that, at the time of this writing, VoIP is outside its legislative purview when the entire call is carried on the Internet. Accordingly, conventional legislation, analogous to the “Do Not Call” list but defending against unwanted VoIP telephone calls, is inapplicable. Furthermore, VoIP lends itself to extreme number portability. A U.S. resident may take a soft phone or VoIP Terminal Adaptor (TA) to a foreign country and place calls (SPIT or otherwise), but for practical purposes the calls originate from a U.S. phone and number. It has already been proven that it is impractical to apply U.S. legislation to offshore calls, making VoIP even more attractive to those sending unwanted “junk” telephone calls, or SPIT. Thus, a legislative solution to the SPIT problem is unlikely.
Accordingly, there is a need for a technical solution for managing unwanted telephone calls employing VoIP. In some ways, the problem of spam over Internet telephony might be likened to email spam. However, defenses against email spam are largely ineffective against SPIT. For example, a unique characteristic of telephony is that if a call is rejected it is gone, whereas email remains on a server indefinitely with no concept of a “conversation” that can be selectively and finally terminated. Moreover, emails are asynchronous and email communications do not generally possess a certificate, thus preventing any certificate exchange and testing. Further, email spammers may readily “set up shop” with a new ID (email address or IP address) whenever email from their former ID has been widely blocked. Therefore, such email spam-fighting schemes as a centralized spammer database, and sending emails to a Junk Mail folder based on senders' email addresses, cannot be successfully applied to VoIP calls.
U.S. Pat. No. 6,330,317 (Garfinkel) discloses a call blocking system for use in assisting implementation of do-not-call lists.
U.S. Patent Application Publication No. 2002/0186683 (Buck et al.) discloses a firewall gateway for VoIT that enables voice data transmission through a firewall that would normally block such transmissions, the scheme involving registration of entities with the Internet telephony service provider.
U.S. Patent Application Publication No. 2003/0021403 (Jones) discloses a “passive” call blocking system in which caller identification information is compared with a caller database, and in which rejected callers are not notified when their calls are being rejected.
U.S. Patent No. 2004/0205135 (Hallam-Baker) discloses an arrangement in which electronic messages are either screened by a referee that discriminates desirable from undesirable messages, or are passed if they include a suitable “credential”.
U.S. Patent Application Publication No. 2003/0152207 (Ryan) discloses a website-based call screening control center in which a website owner can use a menu to limit and control which communications options that outside callers are able to access.
None of the foregoing documents disclose a solution to the problem of spam over Internet telephony. Thus, there is a need in the art to provide a readily implemented arrangement for managing unwanted telephone calls employing VoIP.